This invention relates to the flow control of molten metal and more particularly to continuous flow of molten steel.
A variety of flow controls for molten metals have heretofore been proposed, illustrative of which are those described in U.S. Pat. No. 3,675,911, granted to Walter Kapun on July 11, 1972; U.S. Pat. No. 3,844,453, granted to Henry Eickelberg on Oct. 29, 1974; and U.S. Pat. No. 4,010,876 granted to Robert Steinemann on Mar. 8, 1977. These patents, while teaching the use of multi-compartmented apparatus for controlling metal flow by use of pressurization within one of the compartments, have nevertheless been limited to providing successive batches or sequences of molten metals rather than providing for continuous controlled measured flow. Other proposals have been made for controlling metallic flow from tundishes, illustrative of which is that described in U.S. Pat. No. 4,770,395 granted to Khuong Vo Thanh et al on Sept. 13, 1988. According to one such proposal, "flow from the tundishes into the mold was controlled by a stopper rod suspended above the nozzle entry and linked to a manual lever." Accordingly, there has continued to be a need for apparatus that is long lived, economical and more readily controllable to provide for continuous flow control and flow of molten metal for such applications as continuous casting.